Influence of α‐thalassemia trait on spleen function in sickle cell anemia patients with high HbF

Spleen function was studied in a group of 20 Kuwaiti SS patients (aged 2–12 years), using 99mTc‐labeled tin colloid scintigraphy. They were screened for the α‐thalassemia determinants which are prevalent in the Arabian Peninsula [‐α (3.7 kb) deletion, α2‐globin gene polyadenylation signal (AATAAA → AATAAG) mutation, and 5′ IVS‐I splice junction pentanucleotide (GAGGTGAGG → GAGG) deletion] with a combination of polymerase chain reaction and allele‐specific oligonucleotide (ASO) hybridization techniques. The patients were divided into three groups depending on the result of their colloid uptake. Group I consisted of 7 patients (35.0%) with normally visualized spleens, Group II consisted of 5 (25.0%) with partial visualization, and in Group III there were 8 (40.0%) in whom the spleen was not visualized at all. The significant distinguishing features among those in Groups I and III were mean corpuscular volumes (MCVs) of 74.1 ± 5.1 and 90.1 ± 6.6 fl (P < 0.0001) and mean corpuscular hemoglobins (MCHs) of 22.4 ± 2.7 and 27.5 ± 4.0 pg (P < 0.05), respectively. The overall frequency of α‐thalassemia determinants in the study was 35.0%; however, the frequencies in Groups I, II, and III were 57.1, 30.0, and 18.8%, respectively. α‐Thalassemia trait, therefore, appears to be associated with normal splenic function in these patients. © 1996 Wiley‐Liss, Inc.